
Once.
Tomorrow at nine, the 14th at noon, in two hours.
"Can I set reminders on WhatsApp, in my own words, and have them come at the right hour?" Yes. Type it as you would say it.
Try it freeSee it happen ↓Type it as you would say it: tomorrow at nine, every Monday at eight, thirty minutes before every meeting this week, insist until I confirm. Handled confirms the time in your time zone and the reminder comes back as a normal WhatsApp message. Snooze by replying later.
The chat on the left. What it produced on the right.
Three reminders, three shapes: once, weekly, a rule from the calendar. Each arrives as a normal message.
Four situations people use this for every week.

Tomorrow at nine, the 14th at noon, in two hours.

Monday invoices, Friday timesheets, Sunday call mum.

Thirty minutes before every meeting this week, from the calendar.

Insist until I confirm I sent the receipt.
The first message is never the last. Three things people write in the weeks that follow.
Snoozed. Say for how long, or it picks an hour.
The list, in the chat.
Gone. Nothing else touched.
Nothing to connect. Say your time zone once if it is not obvious from your number. Reminders never count against the free plan's daily messages; setting one does.
Any language you write in. Weekday names and times are understood the way you say them.
It confirms every reminder in your time zone. Travelling? Tell it once.
Reply later, or a time, and it comes back then.
Not yet. Reminders are WhatsApp messages. Calls are on the roadmap.
No. Setting one is a message; the reminder itself is free.
No. It reminds you, and it writes the message for you to forward to them. It never writes to anyone but you.

As you would say it to a person. It comes back confirmed, then it comes back on time. Free to try, no app to install.